module Kernel
  def find_executable?(name)
    ENV['PATH'].split(File::PATH_SEPARATOR).detect {|p| File.executable?(File.join(p, name))}
  end

  def have_postgres?
    if find_executable?("psql")
      if `psql -c '\\l' -U postgres 2>&1` && $?.exitstatus == 0
        true
      else
        warn "No \"postgres\" role? You might need to execute `createuser postgres -drs' first."
        false
      end
    end
  end
end

if defined?(::ActiveRecord::ConnectionAdapters)

  # assert_queries and SQLCounter taken from rails active_record tests
  require 'test/unit'
  class Test::Unit::TestCase
    def assert_queries(num = 1, matching = nil)
      ActiveRecord::SQLCounter.log = []
      yield
    ensure
      queries = nil
      ActiveRecord::SQLCounter.log.tap {|log| queries = (matching ? log.select {|s| s =~ matching } : log) }
      assert_equal num, queries.size, "#{queries.size} instead of #{num} queries were executed.#{queries.size == 0 ? '' : "\nQueries:\n#{queries.join("\n")}"}"
    end
  end

  module ActiveRecord
    class SQLCounter
      def self.ignored_sql
        @@ignored_sql
      end

      def self.ignored_sql=(value)
        @@ignored_sql = value
      end

      self.ignored_sql = [
        /^PRAGMA (?!(table_info))/,
        /^SELECT currval/,
        /^SELECT CAST/,
        /^SELECT @@IDENTITY/,
        /^SELECT @@ROWCOUNT/,
        /^SAVEPOINT/,
        /^ROLLBACK TO SAVEPOINT/,
        /^RELEASE SAVEPOINT/,
        /^SHOW max_identifier_length/,
        /^BEGIN/,
        /^COMMIT/
      ]

      # FIXME: this needs to be refactored so specific database can add their own
      # ignored SQL.  This ignored SQL is for Oracle.
      ignored_sql.concat [/^select .*nextval/i,
        /^SAVEPOINT/,
        /^ROLLBACK TO/,
        /^\s*select .* from all_triggers/im
      ]

      def self.log=(v)
        @@log = v
      end

      def self.log
        @@log
      end

      self.log = []

      def call(name, start, finish, message_id, values)
        sql = values[:sql]

        # FIXME: this seems bad. we should probably have a better way to indicate
        # the query was cached
        unless 'CACHE' == values[:name]
          self.class.log << sql unless self.class.ignored_sql.
            any? { |r| sql =~ r }
        end
      end

      def self.instance
        @instance || self.new
      end
    end

    begin
      require 'active_support/notifications'
      ActiveSupport::Notifications.subscribe('sql.active_record', SQLCounter.new)
    rescue LoadError
      class ActiveRecord::ConnectionAdapters::JdbcAdapter
        def log_info(sql, name, ms)
          ActiveRecord::SQLCounter.instance.call(name, ms, ms, nil, :sql => sql)
          super
        end
      end
    end
  end

end